With higher frequency bands, wireless data communications suffer higher propagation losses for signals between nodes. In order to improve the signal quality and increase the number of simultaneous radios in a noisy environment, many wireless systems use an antenna array with multiple elements. When the same signal is sent through several antennas, the radio beam can be steered by adjusting the phase of the signal at each antenna. More antennas allow the radio beam to be steered with more precision. The same principle applies to receiving signals where the reception can also be steered. In other words by adjusting the phase a receiving antenna may be made especially sensitive to signal coming from a particular direction.
To obtain the benefits of sending and receiving radio signals in particular direction, each radio node in the wireless system must determine the direction to use for each other radio node. This involves trying different directions until a suitable direction is found. With more antennas in an array and more precise beam steering directions, there are more possible directions to try.